Reversing the declinesThe native fi sh of the Murray-Darling Basin have suffered serious declines in both distribution and abundance, particularly in the last 50 years. Close to one-third of the Basin’s 35 native fi sh species are listed as threatened, including Australia’s largest freshwater fi sh, the Murray cod. Eight key reasons for these declines have been identifi ed that pose an ongoing threat to native fi sh populations.

These include fl ow regulation, habitat degradation, poor water quality, barriers that prevent fi sh passage, alien species, disease, exploitation and inappropriate translocation and stocking.

As fi sh are a strong indicator of river health, the poor status of our native fi sh tells us that something is very wrong with the rivers and wetlands upon which the Basin’s communities depend.

Demonstration reaches

Co

ver

cola

ge

John

Mac

kenz

ie (r

iver

sce

ne) a

nd G

unth

er S

chm

ida

(fau

na)

for native fi sh

Snags on the Murray River near Yarrawonga

© J

im B

arre

tt

Typical management interventionsThe good news is that there are things we can do to slow and reverse these declines in both native fi sh populations and river health. These management interventions, which range widely in cost and the amount of resources required, address the threats to native fi sh.

Actions or ‘management interventions’ that can be taken, to manage or remove the impact of these key threats to native fi sh populations include:

Riparian rehabilitation

Riparian areas and vegetation provide habitat and nutrients essential for healthy fi sh populations, together with shade and a buffer for waterways. Riparian rehabilitation activities could include weed management and revegetation, as well as the protection of remnant riparian vegetation.

ResnaggingResnagging involves replacing snags, such as branches and fallen logs, which have been extensively removed from many of the Basin’s rivers. These snags are important for native fi sh breeding, feeding and protection and also provide habitat for other aquatic and terrestrial species.

Alien species controlThere are currently 11 alien species of fi sh in the Basin, such as Carp, Redfi n perch and Gambusia. Alien species can impact on native fi sh through predation, competition for food and space, reducing water quality and transferring diseases. Activities such as biological and chemical control, commercial fi shing, environmental manipulation and habitat improvement for native species aim to reduce the impact of alien species on native fi sh. Control is most effective when several of these activities are undertaken concurrently.

Improving fi sh passageMany species of native fi sh in the Basin have evolved to move large distances both up and down the Basin’s rivers, for example to breed, fi nd food, or to escape unfavourable conditions. However, there are over 4000 structures (such as dams, weirs and culverts) that currently prevent fi sh passage in the Basin. Fishways that are designed to suit Australian river conditions and the swimming abilities of our native fi sh can be built to overcome these barriers.

Water qualitySalinity, excess nutrients, thermal pollution, acidity, turbidity and inadequate water fl ow, are all issues that impact on native fi sh populations and therefore have to be managed appropriately. Rehabilitation and protection of riparian vegetation, management of stock access and changes to land management are some of the ways that water quality may be improved.

© D

ean

Ans

ell

A section of the Darling River near Bourke in need of habitat rehabilitation

Results of tree clearing and desnagging upper Condamine

© D

avid

Mof

fatt

What is a demonstration reach?When carried out in isolation, as is often the case, these management interventions may have a positive effect on native fi sh, but this effect may be small in scale and limited to one or few species. The challenge is: how do we get the best result out of applying these management interventions across the Basin?

One argument is that if we apply a number of these actions in one place, the cumulative benefi t for native fi sh populations and communities will be much greater. This is one of the central ideas behind the demonstration reach concept.

Demonstration reaches are large scale river reaches or wetlands where a number of management interventions are applied to showcase the cumulative benefi ts of river rehabilitation on native fi sh populations.

Current rehabilitation projects relevant to native fi sh are spread thinly across the Murray-Darling Basin, diluting the effectiveness of limited resources.

Demonstration reaches aim to bring these resources together at one place, to maximise the benefi ts of multiple projects.

Demonstration reaches are also a useful way of showcasing the different management interventions that can contribute to improving native fi sh populations.

Demonstration reaches do not involve a reduction in access to, or use of, the river or riverbanks.

© J

im B

arre

tt

Habitat rehabilitation has been shown to benefi t threatened species such as Trout cod

© J

ason

Hig

ham

Local communities, as well as native fi sh, will benefi t from improved river health

Ph 02 6279 0100www.mdbc.gov.au

Measuring water quality

© A

liso

n K

ing

The process of establishing a demonstration reach (Source: Barrett and Ansell 2005)

Electrofi shing on the River Murray

The role of the CommunityDirect community involvement and leadership is essential to the success of a native fi sh demonstration reach. There are many opportunities for hands-on participation.

This involvement could include:

• site selection and management plan development during the planning phase;

• participation in management interventions such as rehabilitation of riparian vegetation during the implementation phase; and

• helping to establish and run a monitoring program, with hands-on involvement in measuring fi sh numbers, water quality, and vegetation responses to management.

How can you get involved?If you enjoy fi shing, are interested in native fi sh rehabilitation, river restoration, or think your local area would suit a native fi sh demonstration reach, we would like to hear from you.

Further informationThe Murray-Darling Basin Commission now has Native Fish Strategy Coordinators in NSW, SA, Victoria and Queensland who can help with the process of establishing a demonstration reach.

Please contact the MDBC on (02) 6279-0100 for further information about demonstration reaches, for a copy of the Native Fish Strategy, and for contact details for your nearest Native Fish Strategy Coordinator.

Resources availableThe MDBC is developing a manual to assist community members and natural resource managers with the process of establishing a demonstration reach. The manual will cover all aspects, from design to implementation, and will contain conceptual and technical information relating to each of the management interventions that may be required for a given reach. If you would like to receive a copy, contact the MDBC.

Barrett, J. (2004) Introducing the Murray-Darling Basin Native Fish Strategy and initial steps towards demonstration reaches. Ecological Management and Restoration, 5, 15-23.

Barrett, J. & Ansell, D. (2005) Demonstration reaches for native fi sh: moving from theory to practice. In I. D. Rutherford, I. Wiszniewski, M. J. Askey-Doran & R. Glazik (Eds.)Proceedings of the 4th Australian Stream Management Conference: linking rivers to landscapes. (pp. 59-67). Department of Primary Industries, Water and Environment, Hobart, Tasmania.

© J

im B

arre

tt

Establish demonstration reach steering committee

Site selection

Establish rehabilitation vision

Development of management plan and communication strategy

Implement management plan

Monitoring and review

Evaluation

I&D

104

09